Mechanical and Tribological Properties of Laminated (NbTaMoW)Nx Films

Laminated (NbTaMoW)Nx films were prepared via co-sputtering. The sputtering variables were a substrate holder rotation speed of 2 and 10 rpm and a nitrogen flow ratio (fN2 = N2/(Ar + N2)) of 0.1, 0.2, and 0.4. The (NbTaMoW)Nx films fabricated at 30 rpm displayed columnar structures. The phase structures of the laminated (NbTaMoW)Nx films varied from multiple body-centered cubic phases to a nanocrystalline and a face-centered cubic phase as the fN2 increased from 0.1 to 0.2 and 0.4. The mechanical and tribological properties of the laminated (NbTaMoW)Nx films were evaluated. The laminated (NbTaMoW)Nx films deposited at an fN2 of 0.4 had hardnesses of 25.2 and 26.1 GPa when prepared at 2 and 10 rpm, respectively, lower than the value of 29.9 GPa for the columnar (NbTaMoW)Nx film prepared at an fN2 of 0.4 and 30 rpm. In contrast, the wear resistances of the laminated (NbTaMoW)Nx films were superior to those of the columnar (NbTaMoW)Nx films.